Rachel Harris has already been cast as Mrs Heffley, the mother of diary-keeper Greg, and Chloe Moretz is also tipped to feature.

The Wimpy Kid books by Jeff Kinney have been a surprisingly huge hit in the publishing world. They have the appearance of being handwritten on lined paper, and are copiously illustrated with scrawly stick drawings. They're a bit like a modern, American version of Goscinny's Petit Nicolas books, although none of Nicolas' gang ever went nuts on jellybeans.

We've not seen much of Gordon yet: he was in National Treasure: Book of Secrets, and The Brothers Bloom. Shooting starts in August and the film is slated for release next spring. If you fancy being an extra, they're holding open casting calls in Vancouver.